Testicular Disorders & Infertility – Impact on Reproductive Function

By (medical director at fertty international), BSc, MSc (embryologist) and (invitra staff).
Last Update: 04/03/2020

Male infertility is defined as the inability of the sperm to fertilize the oocyte and, therefore, cause a pregnancy in the woman. There are several factors that can lead a man to be infertile. Testicular disorders, including damage to the testes, are one of these factors.

By testicular causes for male infertility we refer to the factors that can affect the testicles and have a direct impact on the reproductive function.

Testicular diseases may be caused by congenital disorders, if present from birth, or by external agents that affect the man throughout his lifetime.

Genetic disorders

Sperm formation, also known as spermatogenesis, is a complex process that occurs in the testicles. For this reason, any alteration in their function is likely to alter spermatogenesis and lead to alterations in sperm parameters, including sperm count, motility, morphology, and other defects.

If the cause of testicular failure is congenital (present from birth), it is usually caused by chromosomal alterations or gene mutations. Genetic diseases are likely to be transmitted from parents to children, including infertility.

Infertility or sterility may be acquired in spite of being due to genetic causes. Commonly, this type of infertility is due to problems during fertilization, due to a failed chromosome distribution or recombination. This may result in an embryo that is compatible with life, but that carries a genetic disease.

The following is a list of the most common genetic causes of male sterility that lead to testicular failure:

Y chromosome microdeletion (YCM)

The Y chromosome can only be found on males and is smaller in size than other chromosomes. When an embryo receives the Y chromosome from the father instead of the X, the woman gets pregnant with a boy.

The Y chromosome contains the genes that will lead to the formation of the testicles in a chromosomal region called AZF. Alterations in this region or absence of the most important genes can cause the male to suffer severe testicular factor infertility, often associated with oligozoospermia or complete secretory (non-obstructive) azoospermia.

Moreover, in case these males have children through Assisted Reproductive Technology (ART), it should be taken into account that the futuro baby would also inherit this condition. In other words, he will be infertile.

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Klinefelter syndrome

Klinefelter syndrome (KS) is a chromosomal disease that occurs when males have an extra X chromosome, that is, instead of having an XY pair, the baby has three chromosomes. Given that their genotype is XXY, KS is also known as XXY syndrome.

This leads to a failed development of the male reproductive system and the secondary sex characteristics in boys affected by KS syndrome. Moreover, they will be infertile due to azoospermia.

The treatment of KS involves administering testosterone to promote the development of the muscular anatomy and other male characteristics. However, testosterone does not cure infertility caused by this chromosomal disease.

Get more info by clicking the following link: Klinefelter Syndrome (XXY Syndrome) – Symptoms, Causes & Fertility.

Noonan syndrome

Noonan syndrome (NS) is a congenital disorder due to a mutation of the chromosome 12. It is often inherited from the mother, although it may develop in embryos resulting from gametes of healthy parents.

Children affected by this disorder experience an abnormal development of several body parts like the face and skeleton, in addition to having heart diseases after reaching puberty.

As for its relationship to fertility, NS-affected children can be born with defects in their penis or suffer from cryptorchidism (undescended or maldescended testis).

Diseases & conditions of the testicles

Not all testicular diseases and conditions have a genetic origin. In fact, some of them are diagnosed at birth or, conversely, they appear later in life, even during adulthood.

The following is a list of the most common types of testicular disorders:


It is defined as the incomplete descent of one or both testicles through the inguinal canal into the scrotum.

In children born with this testicular disease, surgery to move the undescended testicle is required before they reach age 2. If this surgical procedure is not done as a baby, the male will experience problems with sperm production due to an elevated temperature of the testicles.

Cryptorchidism might appear during adulthood as a consequence of mumps, causing male infertility.

Get more info by clicking the following link: What Is Cryptorchidism?


It occurs when the veins of the spermatic cord that drain the testicles dilate. It is caused by alterations in the blood flow.

Varicocele may compromise male fertility depending on whether it affects one or both testicles. If only one testis is affected, it develops on the right testicle in 87% of the cases, while only 3% have varicocele on the left testicle. The remaining 10% have bilateral varicocele, in which case the grade of infertility is higher.

Males affected by varicocele can have children successfully after undergoing surgery.

See this for more: What Is Varicocele? - Symptoms & Treatment.

Orchitis or orchiditis

Orchitis or orchiditis is the swelling of one or both testicles due to an infection or a trauma. Unilateral orchitis is the most common type.

The inflammation and increased temperature of the testes that occurs as a consequence leads to an incomplete sperm production process and therefore male infertility, particularly when it is present in both testicles.

When orchitis is caused by an infection (bacterial orchitis), it can be treated with antibiotics. In such case, infertility can be reversed easily. However, mumps can increase the severity of the infertility issue.

In the worst-case scenario, orchitis may cause testicular atrofia, thereby hindering sperm production and causing the testis to be smaller in size.

Learn more: What Is Orchitis? - Definition, Causes & Symptoms.


It is an excessive accumulation of fluid in the spermatic cord, particularly between the two layers that cover the testicle and the inner layer of the scrotum.

Testicular hydrocele may be congenital or acquired as a consequence of trauma, an infection, or cancer. Also, it may be unilateral or bilateral, that is, be present in one or both testicles, and be accompanied by an inguinal hernia.

In all cases, hydrocele may disappear on its own or treated if the patient has symptoms. Although it does not cause infertility by default, it may appear as a symptom of other conditions that do cause male infertility.

Related content: What Causes Hydrocele? - Symptoms & Treatment.

Germ cell aplasia

Germ cell aplasia, also called germinal cell aplasia or Sertoli-cell-only (SCO) syndrome, is a congenital disease that occurs at embryo stage as a consequence of a failure during the formation of the testicles. As a result, the testes are smaller than usual.

It is typically found at or soon after puberty, when the testes are smaller than normal adult testes.

Other external factors

Aside from the causes explained above, there exist other situations that may increase the risk for the man to suffer temporary or permanent infertility. The following are the most frequent ones:

Environmental factors
Environmental pollutants such as street drugs, alcohol, or tobacco can affect the cells that promote sperm production in the testis.
Medications and treatments
Cancer treatments such as chemotherapy and/or radiotherapy can affect the testicles and cause infertility. Other drugs to treat serious diseases can have a negative impact, too.
Laptop use
It may the increase of the temperature and hinder sperm production, since the production function of the testicles is conducted at a temperature of between 2 and 4 °C below the normal body temperature.
A recent study has concluded that bike riding can affect the testicles due to the use of tight clothes and an incorrectly positioned bicycle saddle.

FAQs from users

What are the causes of testicular factor male infertility?

By Dr. María Arqué (medical director at fertty international).

There are numerous factors that can cause male infertility as they affect the production and maturation of sperm in the testicles themselves. These lead to low sperm concentration, low sperm mobility, changes in sperm morphology or failure to produce sperm.

The most common causes of male infertility due to the testicular factor include high testicular temperature, toxins, chromosomal defects or testicular diseases.
Read more

What causes testicular cancer?

By Zaira Salvador BSc, MSc (embryologist).

In most cases, the causes of testicular cancer are unclear. Doctors know that it occurs when healthy cells in the testicle become altered. In other words, it is clear that all testicular cancers begin in the germ cells, but the reasons why these cells become abnormal and develop into cancer are still unknown.

Some risk factors include cryptorchidism, abnormal testicle development, family history, age, and race.

Is male fertility affected in men with only one testicle?

By Zaira Salvador BSc, MSc (embryologist).

Possessing a single testicle, either from birth or due to a later disease such as cancer, does not imply that there is a fertility problem. If the remaining testicle works correctly and the spermatogenesis is not affected, the man will be able to give rise to a natural pregnancy without any problem.

What is testicular torsion?

By Zaira Salvador BSc, MSc (embryologist).

Testicular torsion happens when the spermatic cord rotates and becomes twisted. Some men are born with a higher risk for the condition. Torsion of the testes can occur after an injury to the groin, but also due to rapid growth during puberty.

Males who practice contact sports may also experience testicular torsion. In fact, it is during contact sports when blunt, penetrating, or degloving lesions can occur, which can cause male infertility.

Since testicular torsion causes the blood flow to the testes to stop, spermatogenesis is interrupted within 4 to 6 hours due to a lack of blood flow.

What are the causes of testicular shrinking?

By Zaira Salvador BSc, MSc (embryologist).

Testicular shrinking is associated with the consumption of anabolic-androgen steroids to build up muscle mass. Some anabolic steroids can induce testosterone production, but others can mimic it and lead to testicle shrinkage and even infertility.

Suggested for you

In addition to the conditions and diseases explained herein, there exist a series pre-testicular and post-testicular factors that can lead to male infertility as well. Learn more: Conditions that Cause Male Infertility.

To find out whether the man is fertile or not, he should be properly screened in order to find the potential cause. Get more info by clicking the following link: Male Fertility Testing – How Do You Know if a Man’s Sperm Is Fertile?

There exists a wide range of treatments to fight against male infertility. Obviously, the treatment of choice depends on the cause. Check out this for more information: Treating Male Infertility.

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Authors and contributors

Dr. María Arqué
Dr. María Arqué
Medical Director at Fertty International
Doctorate in Reproductive Medicine at the Autonomous University of Barcelona, specializing in Obstetrics and Gynecology. Dr. María Arqué has many years of experience as a Reproductive Medicine and Gynecologist Consultant and currently works as Medical Director at Fertty International. More information about Dr. María Arqué
Licence number: 080845753
 Zaira Salvador
Zaira Salvador
BSc, MSc
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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